Improvement in chronographs



E. G. BOYNETT. Chronograph.

No. 218,224. Patented Aug.5,18791..

UNTTED STATES PATENT OFFICE E DVARD G. BOYNETT, OF NEv YORK, N. Y.

IMPROVEMENT IN CHRONOGRAPHS.

Sjlecilieation forming part of Letters Patent No. 215,224, dated August 5, 1879; application liled May i, 1ste.

To all 1f-homv 'it may concern:

Be it known that I, EDWARD G. BOYNETT, ol" New York, in the county and State of New York, have invented certain new and usel'ul Improvements in Ghronographs or Timing Attachments for Vatches, of which the following is a specification.

My invention relates to an improved timing attachment tor watches to be used for races and other purposes, and its object is to provide a simple and ett'ective means whereby the second-hand of a watch may be stopped and released at will, whereby it may be instantly turned from whatever position it may occupy to zero.

To this end my invention consists in the con1- bination, with a second-hand ot` a\vatch,nieans lor driving the same, a brake for stopping the same, and a device Vt'or adjusting said secondhand to a startingpoint, oi" a combined lever and plunger, serving the double purpose of shitting the brake andthe said device, whereby the second-hand is at'ljusted to the starting'- point.

It also consists in various details and coinbinations et' parts, whereby the chronograph or timing attachment may be easily manipulated.

In the accompanying drawings, Figure l represents a face View, on an enlarged scale, of a portion ot' a watch embodying my improvements, the dial being' removed and the secondhand turned to the Zero-point; Fig. 2, a similar view, showing' said parts in the act of iinparting motion to the secondhand Fig. 3, a similar view, showing the parts adjusted t'or turning the second-hand to Zero; Fig. il, a transverse section on the dotted line a: 11:, Fig. l, looking in the direction of the arrows; Fig. 5, a detached view ot a plate for supporting certain parts 5 Fig. 6, a view illustrating certain portions of the friction driving device, and Fig. 7 a view ot' the second-hand detached.

Similar letters ot' reference designate corresponding parts in all the 1i gures.

A designates the second-hand arbor or statt ot' a watch-movement, and B a wheel whereby motion is imparted thereto. The said arbor or statt' is supported in proper bearings in the top plate of the watch, and in a plate, C, secured upon the pillar-plate C of the watch, or in the pillar-plate itselt'. The second-hand D,

instead ot' being placed upon the arbor or stati" A, is carried by a sleeve, u, iitting outside the said arbor or stati". rlhe sleeve. here represented 'forms the hub otn a wheel or disk, b, te which it is rigidly secured, and which is provided on its under side with a recess or cavity, as clearly represented in Fig. 4. The said'sleeve c and wheel or disk b tit loosely upon the arbor or stat'fA, so that the latter may turn independently of them, and are connected with said arbor or stai'tl by means ot' a friction driving device, so as to receive motion therefrom when desired.

The driving device here represented consists of a roller, c, rigidly at'tlxed to the arbor or statt' A, and a spring, d, held at one end in a post, c, extending from the wheel or disk b, (see Fig. 6,) and adapted to press upon the said roller c with sutlicient force to cause the said wheel or disk, and with it the second-haml, to rotate with said arbor or staff A.

E designates a brake, adapted to be brought into contact with the wheel or disk I) tor the purpose ot' stopping the latter, or to be removed trom contact therewith in order to release it. It is shown as consisting ot a spring secured at one end to the top plate, Gf, so that its upper end may be swung or adjusted into or out of contact with the wheel or disk l), and preferably having its adjacent face curved to t the periphery ot' the latter, so as to alford a long frictional bearing therewith. ticity ot' the brake causes its 'tace to press on the periphery ot the wheel or disk l), unless otherwise actuated, with sut'lieient torce to stop the latter.

F designates a device, which consists in this instance of a combined lever and plunger, pivoted to the top plate, U, by a screw, f, passing through a slot or elongated hole in the latter, which affords it a longitudinal as well as an oscillating motion, and projecting through the case, when it may be conveniently reached. 1t is provided with a toe,j'1, extending from one side thereof in such a position that by swinging said lever in one direction the toe j is caused to impinge against the brake E and adjust it into the position represented in Fig. 2, out of contact with the wheel or disk b, thereby releasing the latter. By swinging the lever in the other direction the toc j is brought oppo- The elas I will now describe the means whereby theh second-hand is returned to the position of zero or the starting point on the dial. V(Represented in dotted outline at p, Fig. 3.)V

h designates a heartshaped cam, combined with the wheel or disk b, so as to be rotated in unison therewith. Y

It is obvious that the sleeve a, wheel or disk b. and cam h may, with advantage, be formed from one piece of metal, as represented in Fig. 4.

H designates a device shown as consisting of a cam-lever, pivoted to thetop plate, C', at j, and provided with a face, j',.of such shape that on being pressed against the ,cam h, as represented in Fig. 3, it will turn or rotate the latter, whatever its position may be, so as to adjust the second-hand at zero on the dial.

For actuating the cam-lever H, I have shown a spring, I, secured to the top plate, G', and bearing against a toe, h2, extending from the cam-lever H. The cam-actuating lever H is operated by pushing the lever or plunger F longitudinally inward, thereby causing a camshaped face, i, with which it is provided, to pass a toe, h3, upon the cam-lever, and, being opposite said toe, a recess, lr, into which said -toe may project, thus allowing the spring I,

actuating the lever H, to ilnpel the latter against the caln h and turn the second-hand so as to indicate zero. The lever or plunger 'F is moved outward by the resilience of the catch or detent G, and thus, through its face t',

swings the camlever H out of contact with the cam h.

By oscillating the lever or plunger F, I may effect the stopping and starting of the secondhand, and by pushing it inward I may cause the second-hand to return to a position to in dicate zero on the dial. n

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The combination, with a second-hand, means for driving the same, a brake for stopping the same, and a device for adjusting said second-hand to a starting-point, of a combined lever and plunger, serving the double purpose of shifting the brake and the said device, whereby the second-hand is adjusted to the starting-point, substantially as specified.

2. The combination, with the second-hand arbor or sta A, of a sleeve, a, rigidly aiiXed to a wheel or disk, b, mounted upon said arbor or staff and carrying the second-hand, a spring, d, carried by said wheel or disk, roller c, mounted on thesaid arbor or staff, brake E, lever F, provided with the toe f', and the catch or detent G, substantially as specified.

3. The combination, with the second-hand arbor .or sta A, of a sleeve, a, mounted thereon and deriving motion therefrom by means of a friction driving device consisting of a spring, d, carried by said sleeve and bearing upon the periphery of' a roller, c, mounted on the said arbor or staff, a cam, h, affixed to the sleeve a, a cam-lever, H, a spring, I, for actuating said cam-lever, a lever and plunger, F, capable of being pushed inward to release the said cam-lever, and a spring-catch, G, for causing the automatic return of said lever and plunger, substantially as specitied.

E. G. BOYNETT.

Witnesses:

T. J. KEANE, FREDK. HAvNEs. 

